Sensor for monitoring combustion fire of lithium ion battery

The invention relates to a sensor for monitoring combustion fire of a lithium ion battery, comprising a shell and an audible and visual alarm, wherein the shell comprises a mounting base and an accommodating cavity; and the side surface of the accommodating cavity is provided with a plurality of ventilation openings. The sensor further comprises a base arranged on the mounting base and provided with a control system; several smoke gas sensors arranged at the ventilation openings, electrically connected to the control system and used for detecting the smoke degree in the air; a hydrogen fluoride gas-sensitive test paper used for detecting hydrogen fluoride in air and comprising pH test paper, wherein test surfaces are arranged on the surface of the pH test paper at equal intervals, and silicide is uniformly laid on the test surfaces; and a detection mechanism electrically connected to the control system, facing a first driving rotating shaft and used for detecting the color change of the pH test paper. 本发明涉及一种